Triphenylphosphine → [Rac]-3-(4-{2-[2-(3,5-dimethoxy-phenyl)-5-methyl-thiazol-4-yl]-ethoxy}-3,5-difluoro-phenyl)-2-ethoxy-propionic acid ethyl ester

Participants

Reaction Steps

In analogy to the procedure described in example 1 d], [rac]-3-(3,5-difluoro-4-hydroxy-phenyl)-2-ethoxy-propionic acid ethyl ester was reacted with 2-[2-(3,5-dimethoxy-phenyl)-5-methyl-thiazol-4-yl]-ethanol (prepared from [rac]-4-bromo-3-oxo-pentanoic acid methyl ester [PCT Int. Appl. (2001), WO 01/79202] and 3,5-dimethoxy-thiobenzamide [PCT Int. Appl. (1992), WO 92/09586 A1] in analogy to the procedures described in examples 12 a] and 12 b]) in tetrahydrofuran in the presence of triphenylphosphine and DEAD (diethyl azodicarboxylate) to yield [rac]-3-(4-{2-[2-(3,5-dimethoxy-phenyl)-5-methyl-thiazol-4-yl]-ethoxy}-3,5-difluoro-phenyl)-2-ethoxy-propionic acid ethyl ester, which was further saponified in analogy to the procedure described in example 4 e], to yield [rac]-3-(4-{2-[2-(3,5-dimethoxy-phenyl)-5-methyl-thiazol-4-yl]-ethoxy}-3,5-difluoro-phenyl)-2-ethoxy-propionic acid as colorless solid.

Provenance & Evidence